The "Building Envelope" is the area that separates conditioned space from unconditioned space or the outdoors. A building envelope includes all the components that make up the shell or skin of the building. These components separate the exterior of the building from the interior.
You can think of the building envelope as the boundary separating the inside from the outside and through which heat is transferred. Areas that have no heating or cooling sources are considered to be outside the building envelope. A space is conditioned if heating and/or cooling is deliberately supplied to it. For example, walls and doors between an unheated garage and a living area are part of the building envelope; walls separating an unheated garage from the outside are not.
Common measures of the effectiveness of a building envelope include physical protection from weather and climate (comfort), indoor air quality (hygiene and public health), durability and energy efficiency. In order to achieve these objectives, all building enclosure systems must include a solid structure, a drainage plane, an air barrier, a thermal barrier and a vapor barrier for moisture control.
Building envelope design includes four major performance objectives:
In order to determine the amount of a Building Envelope's air leakage a Blower Door Test is performed.
